1. Bacillus D

2. General Characteristics of Bacillus
~ 60 species; Gram-positive or Gram-variable bacilli
Large (0.5 x 1.2 to 2.5 x 10 um)
Most are saprophytic contaminants or normal flora
Bacillus anthracis is most important member
Produce endospores
Aerobic or facultatively anaerobic
Catalase positive (most)
Rapidly differentiates from Clostridium
Bacillus spp. are ubiquitous
Soil, water, and airborne dust
Thermophilic (< 75°C) and psychrophilic (>5-8°C)
Can flourish at extremes of acidity & alkalinity (pH 2 to 10)

3. Diseases Associated with Bacillus

4. Laboratory Characteristics of Bacillus
On blood agar
Large, spreading, gray-white colonies, with irregular margins
Many are beta-hemolytic (helpful in differentiating various Bacillus species from B. anthracis)
Spores seen after several days of incubation, but not
typically in fresh clinical specimens

5. Bacillus anthracis

6. Summary of B. anthracis Infections

7. Summary of B. anthracis Infections (cont.)

8. Epidemiology of Bacillus anthracis
Rare in the US ( , 17 cases reported by CDC)
Enzootic in certain foreign countries (e.g., Turkey, Iran, Pakistan,and Sudan)
Anthrax spores infectious for decades
Biologic warfare experiments (annual tests for 20 years)
Gruinard, off western coast of Scotland
4 x 10e14 fully virulent spores exploded
Eliminated in 1987 (formaldehyde & seawater)
Three well-defined cycles
Survival of spores in the soil
Animal infection
Infection in humans

9. Epidemiology of Bacillus anthracis (cont.)
Primarily a disease of herbivorous animals
Most commonly transmitted to humans by direct contact with animal products (e.g., wool and hair)
Also acquired via inhalation & ingestion
Increased mortality with these portals of entry
Still poses a threat
Importing materials contaminated with spores from these countries (e.g., bones, hides, and other materials)
Usually encountered as an occupational disease
Veterinarians, agricultural workers

10. Epidemiology of Anthrax in Animal and Human Hosts

11. Clinical Presentation of Anthrax Cutaneous Anthrax
95% human cases are cutaneous infections
1 to 5 days after contact
Small, pruritic, non-painful papule at inoculation site
Papule develops into hemorrhagic vesicle & ruptures
Slow-healing painless ulcer covered with black eschar surrounded by edema
Infection may spread to lymphatics w/ local adenopathy
Septicemia may develop
20% mortality in untreated cutaneous anthrax

12. Clinical Presentation of Anthrax Inhalation Anthrax
Virtually 100% fatal (pneumonic)
Meningitis may complicate cutaneous and inhalation forms of disease
Pharyngeal anthrax
Fever
Pharyngitis
Nneck swelling

13. Clinical Presentation of Anthrax Gastrointestinal (Ingestion) Anthrax
Virtually 100% fatal
Abdominal pain
Hemorrhagic ascites
Paracentesis fluid may reveal gram-positive rods

14. Treatment & Prophylaxis
Penicillin is drug of choice
Erythromycin, chloramphenicol acceptable alternatives
Doxycycline now commonly recognized as prophylactic
Vaccine (controversial)
Laboratory workers
Employees of mills handling goat hair
Active duty military members
Potentially entire populace of U.S. for herd immunity

15. Key Characteristics to Distinguish between B
Key Characteristics to Distinguish between B. anthracis & Other Species of Bacillus
Characteristic Bacillus anthracis Other Bacillus spp.
Hemolysis Neg Pos
Motility Neg Pos (usually)
Gelatin hydrolysis Neg Pos
Salicin fermentation Neg Pos
Growth on PEA
blood agar Neg Pos

16. Bacillus cereus

17. Summary of B. cereus Infections

18. Summary of B. cereus Infections (cont.)

19. Gram-Variable Stain of B. cereus with Endospores

20. Foodborne Diseases of B. cereus (Foodborne Infection)
(Intoxication)
(Foodborne Infection)

21. Other Bacillus spp. Bacillus thurigensis Bacillus stearothermophilus
BT corn; Other GMO’s (genetically modified organisms)
Bacillus stearothermophilus
Spores used to test efficiency of killing in autoclaves

22. REVIEW
Bacillus

23. General Characteristics of Bacillus
~ 60 species; Gram-positive or Gram-variable bacilli
Large (0.5 x 1.2 to 2.5 x 10 um)
Most are saprophytic contaminants or normal flora
Bacillus anthracis is most important member
Produce endospores
Aerobic or facultatively anaerobic
Catalase positive (most)
Rapidly differentiates from Clostridium
Bacillus spp. are ubiquitous
Soil, water, and airborne dust
Thermophilic (< 75°C) and psychrophilic (>5-8°C)
Can flourish at extremes of acidity & alkalinity (pH 2 to 10)
REVIEW

24. Diseases Associated with Bacillus
REVIEW

25. Review of Bacillus anthracis

26. Bacillus anthracis
REVIEW

27. Summary of B. anthracis Infections
REVIEW

28. Summary of B. anthracis Infections (cont.)
REVIEW

29. Epidemiology of Anthrax in Animal and Human Hosts
REVIEW

30. Clinical Presentation of Anthrax Cutaneous Anthrax
95% human cases are cutaneous infections
1 to 5 days after contact
Small, pruritic, non-painful papule at inoculation site
Papule develops into hemorrhagic vesicle & ruptures
Slow-healing painless ulcer covered with black eschar surrounded by edema
Infection may spread to lymphatics w/ local adenopathy
Septicemia may develop
20% mortality in untreated cutaneous anthrax
REVIEW

31. Clinical Presentation of Anthrax Inhalation Anthrax
Virtually 100% fatal (pneumonic)
Meningitis may complicate cutaneous and inhalation forms of disease
Pharyngeal anthrax
Fever
Pharyngitis
Nneck swelling
REVIEW

32. Clinical Presentation of Anthrax Gastrointestinal (Ingestion) Anthrax
Virtually 100% fatal
Abdominal pain
Hemorrhagic ascites
Paracentesis fluid may reveal gram-positive rods
REVIEW

33. Treatment & Prophylaxis
Penicillin is drug of choice
Erythromycin, chloramphenicol acceptable alternatives
Doxycycline now commonly recognized as prophylactic
Vaccine (controversial)
Laboratory workers
Employees of mills handling goat hair
Active duty military members
Potentially entire populace of U.S. for herd immunity
REVIEW

34. Review of Bacillus cereus

35. Summary of B. cereus Infections
REVIEW

36. Summary of B. cereus Infections (cont.)
REVIEW

37. Foodborne Diseases of B. cereus (Foodborne Infection)
(Intoxication)
(Foodborne Infection)
REVIEW